EV proliferation/fast charging combined with (hopefully soon) major upticks in battery capacity and V2H and/or V2G to allow significant early morning load shifting based on EV use profiles, could significantly improve our existing US energy structure.

In the 9 months I've owned my Leaf, I've had many thoughtful questions/discussions about the usefulness of a 60 mile range EV. Most would try an EV IF the range was 100 - 150 miles plus, lots of 15-30 min charge stations and a cost competitive with inexpensive compacts. Tough combination, but likely a natural progression to that end.

...A new corridor of 30-minute fast-charge stations launched Monday in Northern California. When it’s fully operational next spring, it’ll include more than 20 locations between Monterey and Lake Tahoe...

Who is funding the project?
As part of its mission to improve energy conservation and promote new energy technologies, Japan’s largest public research and development management organization — New Energy and Industrial Technology Development Organization (NEDO) — is funding “DRIVETHEARC” project...

Too bad very little is being done by our own government or any other entities to provide public DC on the rest of america's interstate highways.

edatoakrun wrote:Do you think this updated announcement (I think the route map is new) amounts to just an extension of the present DC infrastructure east of Sacramento, or maybe something more?

I hope that something was lost in translation in the release below, and that the new DC stations will actually provide opportunities for large numbers of DC Capable BEVs to charge simultaneously (providing reliability) that they will be located where BEV drivers want to use other facilities and that the guidance will allow those seeking DC charging to easily filter out the masses of slow AC sites and unreliable or unavailable DC charge sites.

If you click the link and look at the central California routes mapped, ~only the highway 50 and 80 routes from Sacramento to Tahoe are still lacking DC charge sites (such as they are) so let's hope the new stations proposed on those and the eastern routes are not just more of the same.

NEDO asks Nissan and Kanematsu to analyze EV use in California

...The NEDO project will seek to encourage the use of electric vehicles for longer distances and inter-city driving by installing and maintaining multiple quick chargers along specific inter-city routes. Nissan and Kanematsu will collect and analyze data on EV driving patterns in California, and create a suitable model to help promote more extensive use of electric vehicles in the state and beyond.

With the help of the California state government, and U.S. utility company NRG eVgo*, Nissan and Kanematsu plan to place additional quick chargers at suitable locations along inter-city freeways in Northern California, and use project-specific information services to guide EV users to the most efficient chargers along the route. The companies will then assess whether the combined hardware/software model can successfully encourage users to drive longer distances in EVs.
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Nissan's role in the project will be to install and operate the quick chargers, and analyze any changes in EV use that result

What could you possibly do with a 150 or 320KW charger? On the Leaf, you cant go any faster than the CHADeMO or level 2 charger. Even then, they all say that CHADeMO is bad for the battery.. Are we trying to electrocute Godzilla?

Even if they start increasing the potential rate of charge on new cars in the future, there has to be an electrical (physics-related) limit on how fast you can charge a battery. People seem to be thinking that we will be charging in 5 minutes (like filling up on gas) in the near future... IT IS NOT GOING TO HAPPEN...

Last edited by powersurge on Fri Mar 17, 2017 9:55 am, edited 1 time in total.

powersurge wrote:What could you possibly do with a 150 or 320KW charger? On the Leaf, you cant go any faster than the CHADeMO or level 2 charger. Even then, they all say that CHADeMO is bad for the battery..

Even if they start increasing the potential rate of charge on new cars in the future, there has to be an electrical (physics-related) limit on how fast you can charge a battery. People seem to be thinking that we will be charging in 5 minutes (like filling up on gas) in the near future... IT IS NOT GOING TO HAPPEN...

We try to understand the fast recharge capability of Li-ion batteries and its effect on capacity degradation. We find out that 5 Ah prismatic Li-ion cells can be fully recharged in 3 minutes under a constant rate of 20C, or in 2 min (25.5C) from 0% to 85% SOC (state of charge) without undue stresses. We cycle the battery at 16C charge rate from 0 to 100%SOC and do not see any unexpected battery capacity loss in 50 cycles, where half of the cycles are 1C-rate charge as a reference capacity check. We realize that the batteries under the fast charge study do not experience mass transport limitations in either solid electrodes or the electrolyte system.

If the LEAF had active cooling, I suspect that the batteries would not suffer any significant amount from QC, even if you pushed the charge rate faster. It's the elevated cell temperatures from QC that primarily accelerates the rate of capacity loss.

An optimized charge rate would apply a modified constant current / constant voltage charge profile where it would temporarily allow a higher maximum voltage while charging.

Right now the LEAF limits cell voltages to around 4.12V while charging and doesn't let the cells exceed this. During a QC, this starts limiting the amount of current you can apply well before the pack gets to "100%" due to internal resistance.

But if you let the cell voltages get higher than that, say 4.20V / cell, for example (403V pack voltage), this would allow you to apply more current and charge faster. Periodically you might want to briefly reduce the charge rate to allow the cell voltage to get back down to a normal 4.12V to ensure that you haven't over charged any cells. Or at least you might only apply the "over-boost mode" QC strategy up to a calculated SOC of say 80-90% before reducing current to ensure that you don't have any cells over the normal 4.12V.

Ford must be doing something similar when charging at 16C or 20C in their tests, but probably pushing even higher voltages into the cells.

I hit 397 volts in my 2017 LEAF, but I don't think a LEAF will allow more than 120 amps? I haven't had the new LEAF on a 125 amp charger yet to confirm my fuzzy memory from 5 years without LEAF ownership.

If the LEAF had active cooling, I suspect that the batteries would not suffer any significant amount from QC, even if you pushed the charge rate faster. It's the elevated cell temperatures from QC that primarily accelerates the rate of capacity loss.

It's possible that the cells in my 2017 are the same cells used in the 2018 LEAF (Just double the quantity). That would be 2 cells in series for 30kWh, 3 cells in series for 45kWh, and 4 cells in series for 60kWh.

Anyhoo, I took the new LEAf up to the OC for its maiden voyage. 93 miles each way to Disneyland. I stopped in San Clemente for some electro-juice, and the little LEAF held 100A on the BTC charger until 394 volts and 83%. I'll need a Gidmeter to check out the 125 amp stations.

One note; the battery had 9 temperature bars with ambient temps around 60F on the last of 3 charge stops over about 10 hours.

My own article at HybridCars offers some broader perspectives and comparisons of how VW's plan compares to today's Tesla network both in California and nationally. It also mentions last year's CEC grants which will also help to incrementally expand CHAdeMO/CCS fast charging in California.